EvaluateFunction v1

../_images/EvaluateFunction-v1_dlg.png

EvaluateFunction dialog.

Summary

Evaluate a function on a workspace.

Properties

Name Direction Type Default Description
Function InOut Function Mandatory Parameters defining the fitting function and its initial values
InputWorkspace Input Workspace Mandatory Name of the input Workspace
IgnoreInvalidData Input boolean False Flag to ignore infinities, NaNs and data with zero errors.
DomainType Input string Simple The type of function domain to use: Simple, Sequential, or Parallel. Allowed values: [‘Simple’, ‘Sequential’, ‘Parallel’]
EvaluationType Input string CentrePoint The way the function is evaluated on histogram data sets. If value is “CentrePoint” then function is evaluated at centre of each bin. If it is “Histogram” then function is integrated within the bin and the integrals returned. Allowed values: [‘CentrePoint’, ‘Histogram’]
PeakRadius Input number 0 A value of the peak radius the peak functions should use. A peak radius defines an interval on the x axis around the centre of the peak where its values are calculated. Values outside the interval are not calculated and assumed zeros.Numerically the radius is a whole number of peak widths (FWHM) that fit into the interval on each side from the centre. The default value of 0 means the whole x axis.
OutputWorkspace Output Workspace Mandatory An output workspace.

Description

The algorithm will use the axes of the input workspace to evaluate a functions on them and store the result in the output workspace.

Usage

Example - 1D function and a matrix workspace.

# Load a workspace
ws = Load('MUSR00015189')
# Evaluate a function
EvaluateFunction('name=ExpDecay,Height=56', 'ws_1', StartX=0, EndX=30, OutputWorkspace='out')

Example - 2D function and a MD workspace.

# Create an empty 2D workspace (100 x 100)
nx = 100
ny = 100
ws = CreateMDHistoWorkspace(Dimensionality=2, Extents=[-10,10,-10,10], Names="x,y", Units="U,V",
    NumberOfBins='%s,%s' % (nx,ny),
    SignalInput=[0] * nx * ny, ErrorInput=[0] * nx * ny)
# Evaluate a function
EvaluateFunction('name=UserFunctionMD,Formula=sin(x)*sin(y)','ws', OutputWorkspace='out')

Categories: Algorithms | Optimization